An examination of the heavy metal music subculture that tries to explain why, despite the longevity and popularity of the genre, fans are marginalized and ridiculed for their passion.
Sam Dunn is a anthropologist and a lifelong metal fan. After years of studying diverse cultures, Sam turns his academic eye a little closer to home and embarks on an epic journey into the heart of heavy metal. His mission: to figure out why metal music is consistently stereotyped, dismissed and condemned, even while the tribe that loves it stubbornly holds its ground -- spreading the word, keeping the faith and adopting styles and attitudes that go way beyond the music.
Sam visits heavy metal landmarks as far flung as L.A.'s Sunset Strip, the dirty streets of Birmingham and the dark forests of Norway. Along the way, the two sides of Sam Dunn -- curious anthropologist and rabid fan -- collide, as Sam explores metal's obsession with sex, religion, violence and death, meets his heroes, and discovers some things about the culture that even he can't defend.

In the early 1970s, Sixto Rodriguez was a Detroit folksinger who had a short-lived recording career with only two well received but non-selling albums. Unknown to Rodriguez, his musical story continued in South Africa where he became a pop music icon and inspiration for generations. Long rumored there to be dead by suicide, a few fans in the 1990s decided to seek out the truth of their hero's fate. What follows is a bizarrely heartening story in which they found far more in their quest than they ever hoped, while a Detroit construction labourer discovered that his lost artistic dreams came true after all.

Stonehenge was shaped over centuries, but to what purpose? Was it a temple to the sun, or the moon, an astronomical calendar, or a shrine to dead ancestors? Now Stonehenge may be about to give up some of its secrets. For the first time in nearly half a century a new archaeological dig the sacred stone circle. And the men who are leading the excavation are well aware of the significance of this moment.
The film exposes an investigation into a radical theory that Stonehenge, far from being a place of burial as is commonly assumed, was in fact a place of healing. The investigation takes in forensic testing of bones excavated over the past decades and hard-won permission for the first dig in 50 years at the Henge, watched live online by millions of viewers around the world. Does the theory of the healing stones bear up to modern-day forensic science?

Hear firsthand from individuals struggling with addiction and follow the cutting-edge work of doctors and scientists as they investigate why addiction is not a moral failing, but a chronic, treatable medical condition. Easy access to drugs like heroin, fentanyl, and even prescription medications like OxyContin has fueled an epidemic of addiction - the deadliest in US history. Now, science is revealing how addiction affects the brain, and top experts are gathering evidence about how we should address our drug problem, from embracing evidence-based treatments, to rethinking public policies.

Dr Hannah Fry explores a paradox at the heart of modern maths, discovered by Bertrand Russell, which undermines the very foundations of logic that all of maths is built on. These flaws suggest that maths isn't a true part of the universe but might just be a human language - fallible and imprecise. However, Hannah argues that Einstein's theoretical equations, such as E=mc2 and his theory of general relativity, are so good at predicting the universe that they must be reflecting some basic structure in it. This idea is supported by Kurt Godel, who proved that there are parts of maths that we have to take on faith.
Hannah then explores what maths can reveal about the fundamental building blocks of the universe - the subatomic, quantum world. The maths tells us that particles can exist in two states at once, and yet quantum physics is at the core of photosynthesis and therefore fundamental to most of life on earth - more evidence of discovering mathematical rules in nature. But if we accept that maths is part of the structure of the universe, there are two main problems: firstly, the two main theories that predict and describe the universe - quantum physics and general relativity - are actually incompatible; and secondly, most of the maths behind them suggests the likelihood of something even stranger - multiple universes.
We may just have to accept that the world really is weirder than we thought, and Hannah concludes that while we have invented the language of maths, the structure behind it all is something we discover. And beyond that, it is the debate about the origins of maths that has had the most profound consequences: it has truly transformed the human experience, giving us powerful new number systems and an understanding that now underpins the modern world.

Dr Hannah Fry travels down the fastest zip wire in the world to learn more about Newton's ideas on gravity. His discoveries revealed the movement of the planets was regular and predictable. James Clerk Maxwell unified the ideas of electricity and magnetism, and explained what light was. As if that wasn't enough, he also predicted the existence of radio waves. His tools of the trade were nothing more than pure mathematics. All strong evidence for maths being discovered.
But in the 19th century, maths is turned on its head when new types of geometry are invented. No longer is the kind of geometry we learned in school the final say on the subject. If maths is more like a game, albeit a complicated one, where we can change the rules, surely this points to maths being something we invent - a product of the human mind. To try and answer this question, Hannah travels to Halle in Germany on the trail of perhaps one of the greatest mathematicians of the 20th century, Georg Cantor. He showed that infinity, far from being infinitely big, actually comes in different sizes, some bigger than others. This increasingly weird world is feeling more and more like something we've invented. But if that's the case, why is maths so uncannily good at predicting the world around us? Invented or discovered, this question just got a lot harder to answer.